1. Field of the Invention
The present invention relates to a photographic printing apparatus in which a negative film of continuous length is successively fed out and images thereon are printed on photographic paper.
2. Description of the Prior Art
A typical conventional photographic printing apparatus used to print a negative film of continuous length has hitherto been arranged such that the negative film previously wound on a supply unit is fed out to a take-up unit while passing through a negative film carrier, and images on the negative film passing over a printing gate aperture formed in the negative film carrier are sequentially printed on a roll of photographic paper.
The size of the printing gate aperture of the negative film carrier in the above-described photographic printing apparatus is generally determined in such a manner that the aperture can correspond to a negative film having images of full size (24.times.36 mm) or half size (18.times.24 mm), which is 1/2 of the full size. For this reason, when printing is to be effected from a negative film having images of a size which is different from the predetermined size of the printing gate aperture, it is disadvantageously necessary to remove the negative film carrier from the apparatus body and to mount another negative film carrier suitable for such a negative film.
In order to overcome such a disadvantage, a photographic printing apparatus having a negative film carrier which is capable of corresponding to both full- and half-size images has heretofore been proposed (examples of this type of photographic printing apparatus include Japanese Patent Laid-Open No. 129029/1978).
However, when printing is to be effected from a negative film having images of a size which is different from the full or half size, or a negative film which is not of the continuous length type, it is still necessary in this photographic printing apparatus to remove the negative film carrier from the apparatus body and to mount a special negative film carrier. When negative film carriers are replaced one with another, it is necessary to separate the optical system and the light receiver for color correction from the negative film carrier in order to facilitate the replacing operation. In a printing operation, however, although the optical system may be moved for the purpose of adjusting the focal point, the light receiver needs to remain in its fixed state in order to maintain predetermined photometric conditions.